Heterogeneous catalysis takes place on the surface of catalytic materials and thus the surface structure plays an essential role in catalysis. Establishing the structure-catalysis relationship is the Holy Grail in fundamental catalysis research and the basis for designing better catalytic materials. However, the structural complexity and heterogeneity of traditional catalysts prevents a full understanding of the interplay between the surface structure and catalytic behaviors. Recent advances in nanomaterials synthesis make it possible to achieve nanocrystals with crystallographically defined surface facets and high surface area, which can be considered as ideal model systems for catalytic studies under realistic conditions. In this work, I will showcase how we can make use of ceria nanoshapes as both catalyst and catalyst support to gain molecular level understanding of the shape effect in catalysis through a combination of detailed in situ spectroscopic and kinetic studies. Insights have been gained into how the surface structure of ceria catalyst affects its redox and acid-base properties and those of ceria-supported catalyst. It is suggested that the surface structure of ceria controls the catalytic performance through the structure-dependent surface sites geometry, lattice oxygen reactivity, surface vacancy formation energy, defect sites, and acid-base property on ceria. The study provides fundamental basis for both the improvement of current heterogeneous catalysts and the design of highly efficient catalyst via shape control without changing the catalyst composition.

Understanding shape effect in catalysis: A case study of ceria nanoshapes as catalyst and catalyst support

248th National Meeting (2014)

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